Dental mallet



E.V C. EEEISTEE.

DENTAL MALLET.

(No Model.)

UNITED STATES PATENT OFFICE.v l

HENRY C. REGISTER, OFPHILADELPHIA, PENNSYLVANIA.

DENTAL MALLET.

SPECIFICATION forming part. of Letters Patent No. 363,911, dated May 31, '1887. y

Application filed February 1S87. kSerial No. 226.375. (No model.)

To @ZZ whom, #may concern:

Be it known that I, HENRY'G. REGISTER, a citizen of the United States, residing in the city and county of Philadelphia, in the State ot' Pennsylvania, have invented an Improvement in Dental Mallets, of which the following is a specification.

The object of my invfention is the construction of a simple, accurate, and easily operated mallet which shall be reliable in its action and not liable to get out of order.

My invention is an improvement upon a dental plugger patented to me August 24th, 1886, in and by United States Letters Patent No. 347 ,828.

My patented plugger .comprehends, in a dental mallet, the combination of abit-actuating plunger, an impact wheel, and a roller or Sphere which is housed within said wheel and a portionv of theperiphery'or surface of which projects beyond the periphery of said impact wheel. The said bit-actuating plunger is contained within a cylindriform thimble screwed into the kupper portion of the casing and adapted to be raised or lowered to adjust the set of its contained plunger by rotating it by its head or upper portion which projects above the upper extremity of the casing.

My present invention relates especially to means for adj listing the aforesaid thimble, and

it also comprehends the application to the plunger of an antifriction roller or sphere, as well as certain other features of construction -hereinafter described and claimed.

A mallet conveniently embodying my improvements is represented in the accompanying drawings and described in this specification, the particular subject matter claimed `as novel being hereinafter delinitely specified.

In the drawings, Figure l is a central, vertical, longitudinal, sectional, side elevation through a mallet embodying my invention, and provided with an electrcally-actuatedimpact wheel,and a bit-actuating plunger provided With a cylindriform roller. Fig. 2 is a vertical transverse sectional elevation through the impact wheel and its headand enclosing envelope shown 'in Fig. l, in the plane of the dotted linea-x of said'gure,-the thimble and its adjusting collar and a portion of the socket piece being, however, represented in side elevation. Fig. 3 is a top plan view of fied form of application, ofthe collar for operating the bit clamping jaws. Fig. 6 is a fragmentary sectional elevation of the thimble and neighboring parts; and Fig. 7 a similar view ofthe body chamber, bushing spring, and neighboring parts.

Similar letters of reference indicate corresponding parts.

In the drawings, A represents thc casing, conveniently composed of a body ofvulcanite,

the thimble shown in Figs. l and 2, section v which isdesignated by the said letter A,and l of a ferrule AX screwed or otherwise suitably applied to the lower extremity of said body. The casing proper, which includes both body and ferrule, is axially apertured to contain a cylindri form bushing B, preferably made otmetal,and terminating at its lower extremity in any suitable bit-clamping chuck, conven ientl y a series of spring jaws b of any preferred construction. The lower extremity of the ferrule is recessed to form an annular ferrulechamber ax, which contains what I term a collar spring c2, encircling the bushing, and adapted to act between the under surface ot' an externally projecting circumferential ange which I term the 'lower dange b2, xedly applied to the bushing, and the upper extremity of a sliding collar G encircling the bushing, A

entered as to itsupper extremity within the 'ferrule chamber, and adapted to compress the springjaws b upon the bit D (represented in dotted linesin the drawing) when forced down upon said jaws by the thrust of the collar spring c2 acting, as stated, against the lower an'ge b2 as an abutment.

At the region of the joint between the body and ferrule-of the casing, an annular chamber, which I term the body chamber a, Figs. l and 7, is .formed within the inner walls ofthe casing,-within which is incloscd a spiral spring, which I term the bushing spring c3, which abuis between the base of the body chamber and an upper fiange b, similar to the lower flange b2, applied to the exterior of .the bushing. Normally, the bushing spring serves to maintain the bushing and its contained bit in an elevated position, by maintaining the upper ange b3 against the top of the body chamber, as shown in Fig. l.

A portion of the body of the casing,r is eut away or opened to form a thumb space a exposing for a portion of its length the bushing, which is, as to such exposed portion, provided with a thumb knob b, or equivalent projecjection, depression, or linger surface, by means of which the bushing can be manually forced downward, compressing the bushing spring, and, for the time being, removing the bit from range of contact with the plunger, notwithstanding the' continued reciprocation of the latter under a continuing rotation of the impact wheel.

The upper portion of the easing is closely surrounded by a swivelled adjusting collar E, maintained against vertical displacement by a swivel stud c passing through it into a circumferential recess c' formed on the exterior of the casing. The lower internal surfaces of the adjusting collar are cylindriform to afford a bearing for rotation of the collar upon the casing, while its upper internal surfaces are provided with a screw thread cl for engagement with the externally-threaded thimble F,

-whicli is, by such engagement of threa'ls, supported above the casing.

The thimble contains a bit-acuatiiig plunger G, capped or surmounted by a sphere, roller,

or-anti-friction-wheel, to ease, by its capacity for rotation, the contact of the roller or sphere -of the impact wheel, which in my former patented invention encountered the upper extremity of the plunger direct. I

In order conveniently to admit of the introduction of the plunger and its sphere within the thimble, the latter is preferably'made in two' parts socketed and threaded together as clearly represented in Figs. 1 and 6.

The office of the adjusting collar E, being, by its rotation under application of the operators fingers, to raise and lower the thimble to adjust the set of the plunger with respect to the sphere ofthe impact wheel, it is obvious that the thimble, while free to move vertically in either direction, must be maintained against rotation,and this I conveniently accomplish by providing said thimble with depending thimble lugs f adapted to be entered and to move vertically within lug seats la in a socket piece H, from which spring the side or fork bars I of the head for supporting thejournals i of the impact wheel J.

rIhe socket piece is conveniently provided with a depending' cylindriform socket ange h which is closely iitted over the upper extremity of the adjusting collar E, and is swivelled with respect thereto by the swivel stud h entered within a recess h2 on the exterior of the adjusting collar. rlhe (it of the socket iiauge with respect to the adjusting collar, and of the adjusting collar with respect to the casing, should be so exact as to prevent play.

The impact wheel proper being simply a device'for carrying a sphere, roller, or equivalent anti-friction contrivance L so housed within it that a portion of its periphery or surface project-s beyond the peripheryof the Wheel, it is manifestly inconsequential how the said wheel be formed and operated, and, in Fig. 4, I have represented it simply as a solid disk or wheel, adapted to be actuated by a"driving cord passed over apulleyjformed or connected with it, while in Figs. 1 and 2 I have represented it as an electricallyoperated disk, substantiallyin the form of the armature of au electric motor. In this latter form the body ofthe armature or impact wheel or disk proper, to which the letter J is applied and which is provided with the peripheral sphere, orroller L, is formed of vuicanite and contains `four embedded bobbinsjx, being also provided with a commutator]`2 Fig. 2, of which the brushes are designatedj. Iole pieces y" f ofa mag' netic field are likewise suitably applied, and preferably supportedby an enclosing envelope K of vulcanite which springs from the socket piece and envelopes the entire impact wheel and upper portion ofthe instrument, as shown in Figs. l and 2. p

The axle ofthe armature is designated j, and is at its axial extremities conically recessed to it it to receive cone-pointed journalsi applied, as stated,in any preferred manner to the fork bars I, which spring from the socket piece.

All circuit connections save only the wires upon the cores of the bobbin, which are shown in section, are for clcarness of illustration omitted, but binding posts k applied to the enclosing envelope are represented. It is to be understood that the usual connections are employed.

In Fig. 4 I have represented the side or fork bars I, which together and in connection with the socket piece of which they form a part, form the forked head of the implement, as extending only far enough to carry the journals of the impact wheel, while a supplemental fork M, completing the enclosure of the wheel, is likewise applied to the journals.

In Fig. 5 I have represented the collar C, which, in the construction already described, is actuated to clamp the springjaws upon the bit by the thrust of a collar spring,as internally threaded to thread upon an externally threaded bushing terminating in spring jaws, by which construction the collar spring can be dispensed with, and the jaws of the bushing, which form a clamp chuck, be clamped upon the bit by the rotation of said threaded collar.

In addition to the foregoing modifications, it is obvious that many changes in form and construction of the various parts may readily be made. Thus, while it is convenient to provide the thimble with lugs to prevent its rotalOO tion, it may, while being freek to move vertically, be retained against rotation by an external feather'or key, or by many other cout rivances obvious to a mechanic.

The mode of construction of the thimble is not, of course, essential. That represented is a convenient form, but, as'is apparent, the plunger alone or the plunger and its sphere may be retained within it bya cap or bushing applied to either extremity of the thimble, thel latter in such instances being made solid.

The form of the socket piece and of the head proper of the mallet may likewise be varied. It is obvious that while the bushing is a convenient contrivance for enabling the operator to temporarily throw'the bit out of range of engagement with the plunger, yet that the plunger when equipped with a sphere or roller applied to a thimble constructed and operated in the manner herein set' forth is operative with mallets unprovided with the bushing and its connected contrivances.

Having thus described my invention, I claim i l. In a dental mallet, the combination of a bit-actuating plunger, a sphere or roller surmounting said plunger, van impact wheel, and a sphere or roller which is housed within said wheel, and a portion of the periphery or surface of which projects beyond the periphery of said impact wheel, substantiall y as set forth.

2. In a dental mallet, in combination with a casing, a thimble applied to the upper portion` of the casing and adapted to be adjusted longitudinally with respect to said casing, a

-plunger contained in said thimble, a, sphere or roller surmounting said plunger, an impact wheel,and a sphere or roller which is housed within said wheel and a portion of the periphery or surface of which projects beyond the periphery of said impact wheel, substantially as set forth. j

3. In a dental mal1et,.in combination with a casing, a thimble applied to the upper portion of the casing and adapted to be adjusted longitudinally with respect to said casing, a plunger contained in said thimble, an adjusting collar applied to the casing and threading with respect to the thimble so as vto be adapted when rotated to adjust the vertical set of said thimble, suitable means for maintaining the thimble against rotation, an impact wheel, and a roller or sphere which is housed within said wheel and a portion of the periphery or surface of which projects beyond the periphery of said impact wheel, 'substantially as set forth.

4. In a dental inallet, in combination with a casing, a thimble applied to the upper portion of the casing and adapted to be adjusted longitudinally with respect to said casing, a plunger contained in said thimble, a sphere or roller surmounting said plunger, an adjusting collar applied to the casing and threading with respect to the thimble so as to be Vadapted when rotated to adjust the Vertical set of the thimble, suitable means for maintaining the thimble against rotation, an impact wheel, and a roller or sphere which is housed within said wheel and a portion of the periphery or surface of which projects beyond the periphery of said impact wheel, substantially as set forth.

5. In a dental mallet, in combination with va casing, anlexternally threaded thimble, a

casing apertured throughout and formed with a thumb space or opening exposing its aper- -ture,a bushing adapted to the aperture, ca-

pable of end for end movement within the-casing, terminating in a bit clamping chuck,and provided with a thumb knob or equivalent -finger contrivance presenting through the opening. in the casing-a spring for normally maintaining the bushing in an elevated position,-a bit-actuating plungerf-and means for supporting and reciprocating said plunger, substantially as and for the purposes set forth.

7. In a dental mallet, the vcombination of a casing apertured throughoutand ehamberedat its lower extremity,-a bushing adapted to the aperture of the casing and terminating in spring jaws, -a collar applied to said'bushing above the spring jaws,-and a spring contained within the chamber of the casing and adapted by thrust between said collar and an abutment on the bushing to cause the collar to compress the jaws-substantially as set forth.

S. In a dental mallet, in combination with a casing apertured throughout, formed with a thumb piece or opening exposing its aperture, and chambered at its lower extremity,- a bushing adapted to the aperture, capable of end for end movement within the casing,ter

minating in a bit-clamping chuck, and provided with a thumb knob or-equivalent finger 'contrivance presenting through the opening in the casing,-a collar applied to said bushing above the bit-clamping chuck,-a. spring contained within the chamber of the casing and adapted by thrust between the collar and an abntinenton the bushing to cause the collar to compress the jaws,a spring for normally maintaining the bushing in an elevated positiem-a bit actuating plunger above the casing,-and means for supporting and reciproroo eating said plunger, substantially as and for the purposes set forth.

9. In a dental mallet, the following elements in combination,-an.apertured casing having a thumb space or opening exposing its aperture,-a bushing adapted to the aperture in the casing and terminating in a bit clamping chuck,-a bushing spring contained within the casing and adapted to maintain the bushing normally at a given elevation,--a swiveiled adJl usting collar applied to the casing and the periphery orsurface of which projects be- 1o adapted to adjust the vertical set of a thirnyoud the periphery of said impact wheel, subble,-a. thirnble containing a bitactuatingstantiaiiy as set forth. piunger,-n1cans for maintaining the thimble In testimony whereof I have heren nto signed 5 against rotation,-a mallet head `supported my name this 25th day of January, A. D., 1887 above the adjusting collar and swivelled With HENRY C REGISTER, respect thereto for carrying an impact Wheel,- In the presence of an impact Wheel, -and a roller or sphere Wh ich J BoNsALL TAYLOR is housed within said wheel, and a portion oi i JOHN JOLLEY Jr 

